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Biomedical subjects

G Zhou

Publications and source records attributed to G Zhou.

At least 55 records · Page 3Linked to original sources
PubMed2001

Uroplakin Ia is the urothelial receptor for uropathogenic Escherichia coli: evidence from in vitro FimH binding.

The binding of uropathogenic Escherichia coli to the urothelial surface is a crucial initial event for establishing urinary tract infection because it allows the bacteria to gain a foothold on the urothelial surface, thus preventing them from being removed by micturition. In addition, it triggers bacterial invasion as well as host urothelial defense. This binding is mediated by the FimH adhesin located at the tip of the bacterial type 1-fimbrium, a filamentous attachment apparatus, and its urothelial receptor. We have prepared a biotinylated, recombinant FimH-FimC adhesin:chaperone complex and used it to identify its mouse urothelial receptor. The FimH-FimC complex binds specifically to a single 24 kDa major mouse urothelial plaque protein, which we identified as uroplakin Ia by mass spectrometry, cDNA cloning and immunoreactivity. The terminal mannosyl moieties on Asn-169 of uroplakin Ia are responsible for FimH as well as concanavalin A binding. Although FimH binds to uroplakin Ia with only moderate strength (K(d) approximately 100 nM between pH 4 and 9), the binding between multiple fimbriae of a bacterium and the crystalline array of polymerized uroplakin receptors should achieve high avidity and stable bacterial attachment. The FimH-FimC complex binds preferentially to the mouse urothelial umbrella cells in a pattern similar to uroplakin staining. Our results indicate that the structurally related uroplakins Ia and Ib are glycosylated differently, that uroplakin Ia serves as the urothelial receptor for the type 1-fimbriated E. coli, and that the binding of uropathogenic bacteria to uroplakin Ia may play a key role in mediating the urothelial responses to bacterial attachment.

Adhesins, Bacterial↗
PubMed2001

Generation of high-quantity and quality tag/ditag cDNAs for SAGE analysis.

The serial analysis of gene expression (SAGE) technique is an important tool for genome-wide gene expression analysis. However, the requirement of a large amount of mRNA for the analysis and the difficulties in generating high-quality tag and ditag fragments for the construction of a SAGE library often interfere with the successful performance of the SAGE technique. We developed two procedures to solve these issues: (i) introducing low-cycle PCR amplification of the 3' cDNA before the BsmFI digestion of the 3' cDNAs and (ii) gel purifying the BsmFI-released tag fragments before ditag formation. These modifications provide a large quantity of initial 3' cDNAs and high-quality tags and ditags for the construction of SAGE libraries.

Cloning, Molecular↗
PubMed2001

Carcinogenic potential and genomic instability of beryllium sulphate in BALB/c-3T3 cells.

Occupational exposure to beryllium (Be) and Be compounds occurs in a wide range of industrial processes. A large number of workers are potentially exposed to this metal during manufacturing and processing, so there is a concern regarding the potential carcinogenic hazard of Be. Studies were performed to determine the carcinogenic potential of beryllium sulfate (BeSO4) in cultured mammalian cells. BALB/c-3T3 cells were treated with varying concentrations of BeSO4 for 72 h and the transformation frequency was determined after 4 weeks of culturing. Concentrations from 50-200 microg BeSO4/ml, caused a concentration-dependent increase (9-41 fold) in transformation frequency. Non-transformed BALB/c-3T3 cells and cells from transformed foci induced by BeSO4 were injected into both axillary regions of nude mice. All ten Be-induced transformed cell lines injected into nude mice produced fibrosarcomas within 50 days after cell injection. No tumors were found in nude mice receiving non-transformed BALB/c-3T3 cells 90 days post-injection. Gene amplification was investigated in K-ras, c-myc, c-fos, c-jun, c-sis, erb-B2 and p53 using differential PCR while random amplified polymorphic DNA fingerprinting was employed to detect genomic instability. Gene amplification was found in K-ras and c-jun, however no change in gene expression or protein level was observed in any of the genes by Western blotting. Five of the 10 transformed cell lines showed genetic instability using different random primers. In conclusion, these results indicate that BeSO4 is capable of inducing morphological cell transformation in mammalian cells and that transformed cells induced by BeSO4 are potentially tumorigenic. Also, cell transformation induced by BeSO4 may be attributed, in part, to the gene amplification of K-ras and c-jun and some BeSO4-induced transformed cells possess neoplastic potential resulting from genomic instability.

3T3 Cells↗
PubMed2001

[Carbon equilibrium in Larix gmelinii forest and impact of global change on it].

In order to provide a methodological demonstration for the study of C cycle in forest, the CENTURY model was applied to simulate the C cycle in Larix gmelinii forest and to approach the impact of global change on it. The results showed that the Larix gmelinii forest served as a C sink, with an annual net absorption of 2.65t.hm-2. Climate change and increased atmospheric CO2 concentration benefited for the net primary production (CNPP) and net C absorption capacity of forests in North China. When the atmospheric temperature was increased by 2 degrees C, the gross biomass and NPP of Larix gmelinii forest increased, while soil C content decreased, and the variation of these three indices was bigger when the precipitation was decreased by 20% than increased by 20%, indicating that the limiting factor for the forest growth in this area is atmospheric temperature, while precipitation is abundant or even too much.

Carbon↗
PubMed2001

[Characteristics of litter and its contained water in three succession communities in Dinghushan Mountain].

Studies on the characteristics of litter and its contained water in three succession communities in Dinghushan Mountain showed that the standing mass of litter was in the order of pine forest > mixed forest > broad-leaved forest, and the annual litterfall was broad-leaved forest > mixed forest > pine forest, indicating that the return rate of nutrients was lower in pine forest than in broad-leaved forest. The proportion of leaf litter decreased in the order of pine forest > mixed forest > broad-leaved forest, and that of branch, flower, and fruit litter was on the contrary, because the broad-leaved forest had the largest amount of branches and the biggest scope of canopy. The staturation water content of litter in pine forest, mixed forest and broad-leaved forest was 329.0%, 313.0% and 295.0%, respectively, showing no significant difference, but the water content of litter in three communities differed significantly, followed the order of broad-leaved forest > mixed forest > pine forest. The evaporation ratio of litter water to free water in broad-leaved forest, mixed forest and pine forest was 78.9%, 82.45% and 91.22%, respectively.

Biodegradation, Environmental↗
PubMed2001

[Characteristics and quantitative simulation of stomatal conductance of Aneurolepidium chinense].

Based on field measurements of stomatal conductance and photosynthesis of Aneurolepidium chinense, the dynamic characteristics and the relationship between stomatal conductance and environmental conditions were examined to develop a leaf stomatal conductance model for A. chinense. The results showed that the variation of stomatal conductance of A. chinense was closely correlated with environmental factors, such as physiologically active radiation (PAR), vapor pressure deficit (VPD) and air temperature (Ta). The daily variation of A. chinense stomatal conductance could be described as M-type curve at fair-weather, but [symbol: see text]-type curve at cloudy weather. The value of stomatal conductance increased with the increase of PAR or Ta, but decreased with the increase of VPD. The relationship between stomatal conductance(gs) and environmental factors could be expressed as: gs = PAR(2.01 Ta2 + 147.74 Ta2321.11)/((444.62 + PAR)(-538.04 + VPD)). This model would be helpful to simulate the dynamical photosynthesis of leaf and canopy and to further simulate the NPP of ecosystems and the exchange of water and heat among the soil-plant-atmosphere continuum.

Computer Simulation↗
PubMed2001

[Microskin grafting in recent 15 years].

OBJECTIVE: To summarize microskin grafting in recent 15 years. METHODS: Microskin grafting was performed in 162 patients with extensive burns. The indications and forms of the grafting, mechanization in making microsk in and outcome of wound recovered by micrografts were discussed. RESULTS: Extremely extensive third degree burns, common extensive third degree burns and extensive granulation wound were healed byn different ways of microskin grafting. A new machine was used to mince micrografts with good clinical results. The homografts as coverture was exfoliated in either necrosis or desquamation. Scar formation was related to wound repair. CONCLUSIONS: Microskin grafting has made progress in recent years. The orientation and even spread of micrografts are very important for good wound repair. The technic should be further improved.

Adolescent↗
PubMed2001

Monoclonal anti-idiotype antibody bearing the internal image of nasopharyngeal carcinoma associated antigen.

OBJECTIVE: To generate and characterize anti-idiotypic monoclonal antibody (Ab2) that bears the internal image of nasopharyngeal carcinoma (NPC) associated antigen. METHODS: Using NPC monoclonal antibody (Ab1) as immunogen, hybridoma cells were obtained by fusion of SP2/0 myeloma cells with immunized murine spleen cells. Positive clones were screened by Sandwich ELISA and a binding inhibition test. To determine whether Ab2 possess the internal image of the original antigen or not, mice were immunized with Ab2. ELISA and the competitive inhibition assay tested anti-anti-idiotypic antibodies (Ab3) in anti-sera. Cell-mediated immunity to tumors induced by Ab2 was investigated by a delayed-type hypersensitivity response and the mouse T-cell proliferation assay. RESULTS: Anti-idiotypic monoclonal antibodies against the monoclonal anti-NPC antibodies FC2 and HNL5 were generated that recognize NPC associated antigens. These Ab2, which were designated 2H4 and 5D3, could inhibit the binding of FC2 or HNL5 to NPC cell lines. Anti-sera from the immunized mice, which contained Ab3, could compete with FC2 or HNL5 for binding with NPC cell by a competitive inhibition assay. Mice immunized with 2H4 or 5D3 coupled with keyhole limpet hemocyanin (KLH), showed a positive and specific delayed-type hypersensitivity (DTH) reaction after stimulation by NPC cells. The mouse T cell proliferative assay indicated that there was a significantly higher proliferative response of the splenocytes in the experimental groups than that in control groups. CONCLUSIONS: Anti-idiotypic antibodies 2H4 and 5D3 are Ab2 beta bearing the internal image of the epitope of NPC associated antigen. Either 2H4 or 5D3 expressing three-dimensional shapes that resemble the structure of natural antigens could induce humoral and cellular immune response.

Animals↗
PubMed2001

[Analysis on ecophysiological characteristics of leaf photosynthesis of Aneurolepidium chinense in songnen grassland].

A series of physiological characteristics of leaf photosynthesis and environmental factors are measured on Aneurolepidium chinense in Songnen salinized grassland during the growth season. The results showed that the daily change pattern of net photosynthetic rate (Pn) of Aneurolepidium chinense could be expressed as a two-humped curve, the daily change pattern of transpiration rate is one-humped curve. In addition, net photosynthetic rate (Pn), transpiration rate (E) and stomatal resistance (Rs) are affected by various environmental factors. At different growth stage, the influence of environmental factor on them is different, and even the same environmental factor had an different effect on Pn, E and Rs. In the whole growth period, photosynthetic available radiation (PAR) was the most intensive effect on the photosynthesis of Aneurolepidium chinense. Among Pn, E and Rs, E was one of the most obvious ecophysiological factor affected by environmental factors.

China↗
PubMed2001

[Pharmacological study on the extracts from Typhonium flagelliforme Blume].

OBJECTIVE: To study the pharmacological action of Typhonium flagelliforme Blune(TFB). METHODS: Relieving a cough and eliminating expectoration were observed by strong aqua spray and pheol red determining methods. The antiasthmatic action was observed by whole spraying method. The analgesia and anti-inflammation were studied by the twisting test induced by acetic acid and ear swelling induced by xylene. The sedation was determined by autonomic action test. The toxicity of TFB was studied through the acute toxicity test in mice. RESULTS: All the water, alcohol and ester extracts of TFB could significantly decrease cough times, increase phenol red outage in trachea, prolong asthma incubation period, decrease twisting times, inhibit ear swelling and decrease autonomic action times. CONCLUSION: All water, alcohol and ester extracts of TFB have effects of relieving a cough, eliminating expectoration, antiasthmatic, analgesia, anti-inflammation and sedation. The maximum tolerances of TFB for acute toxicity were 720 g/kg(water extract), 900 g/kg (alcohol extract) 3240 g/kg(ester extract) respectively.

Analgesics↗
PubMed2001

[Study on diarrhea disease and Escherichia coli strains harboring HPI pathogenicity island of Yersinia enterolitica in Shandong province].

OBJECTIVE: It was found that some E. coli strains previously identified as entero SLTs-producing and invasive E. coli (ESIEC), harboring HPI pathogenicity island of Yersinia enterolitica. This research was designed to reveal prevalence, susceptible group and clinical features it caused. METHODS: All of the diarrhea patients were from the out-patient units of four hospitals in Shandong province from June to November of 1997. Stool specimen were collected before administration of antibiotics for isolation of enteric bacterial pathogen. Clinical symptoms were recorded at the same time. RESULTS: A total number of 449 enteric pathogenic bacteria strains were detected among stool samples from 671 patients, with isolation rates of Shigella species and diarrheagenic E. coli 25.48% and 15.05% respectively. When irp-2 and ipaB gene fragments were used as DNA probes, 42 of 176 un-identifiable strains were found irp-2(+) and ipaB(-), which were identified as HPI-harboring E. coli. Typical symptoms of the diarrhea caused by HPI-harboring E. coli were described as mild, including abdominal pain, shiver and vapidity. Temperature of the patients was usually normal. Over 6 times of bowel movements per day was frequently observed, of which most were unformed stools with mucous. CONCLUSION: HIP-harboring E. coli was an important diarrheagenic pathogen identified from 671 patients with diarrhea. Shigella was found to be the majority strain.

China↗
PubMed2001

[Indomethacin induces apoptosis of K562 cells through activation of caspases and elevation of intracellular free calcium].

OBJECTIVE: To investigate the indomethacin (IN) induced apoptosis of K562 cells: (1) the expression, activation and subcellular localization of caspase-3 and -8; (2) the change of intracellular free calcium concentration ([fCa(2+)]i) and its mechanism; and (3) whether the cell apoptosis is cyclooxygenase (cox) dependent or not. METHODS: Changes and subcellular localization of caspase-3 and -8 were observed by laser scanning confocal microscopy (LSCM); expression and activation of caspase-3 and -8 proteins by Western blotting; changes of intracellular [fCa(2+)]i by LSCM coupling with a calcium-fluorescence probe and calcium chelator EGTA blocking test; and cox inhibitor effect by MTT assay. RESULTS: (1) LSCM assay and Western blotting showed that caspase-3 and -8 localized in cytoplasm and nucleus dispersedly and spottedly and were upregulated with the increasing of IN doses. Western blotting also showed the cleavage and activation of caspase-3 and -8 during IN-induced apoptosis. (2) The increase of [fCa(2+)]i in K562 cells was parallel to the increase of IN concentration regardless of the presence or absence of EGTA. But with EGTA treatment, [fCa(2+)]i was much less than that without EGTA treatment. (3) Low dose of IN or other cox inhibitors could not exert cytotoxic effects on K562 cells whereas high dose of IN could. CONCLUSION: (1) The upregulation and activation of caspase-3 and -8 play a fundamental role in apoptosis induced by IN in K562 cells. Both cytoplasm and nucleus are locations where caspase-3 and -8 localized. (2) The increase of [fCa(2+)]i may be critical in the modulation of apoptosis; the extracellular calcium influx is the main source of the elevation of [fCa(2+)]i in K562 cells and can be blocked by the calcium chelator EGTA;the release of calcium from intracellular calcium store is also an important source of the intracellular calcium which can trigger apoptosis without the extracellular calcium influx. (3) Apoptosis of K562 cells induced by IN is cox-independent.

Apoptosis↗
PubMed2001

Nucleotide sequences of the coat protein and readthrough protein genes of the Chinese GAV isolate of barley yellow dwarf virus.

The nucleotide sequences of the coat protein (CP) and readthrough protein (RTP) genes of the Chinese GAV isolate of Barley yellow dwarf virus (BYDV) were determined. The CP and RTP genes of GAV isolate comprised 600 and 1374 nucleotides, respectively. When the CP and RTP gene sequences of GAV isolate were compared with those of BYDV isolates MAV-PS1, P-PAV, NY-SGV and Cereal yellow dwarf virus RPV (CYDV-RPV), the highest similarity (97.2%) between the CP genes of GAV and MAV-PS1 isolates was observed, while the RTP genes of these two isolates shared a lower similarity (87.8%). The results of the alignment of the deduced amino acid sequences of RTP showed that the sequence diversity observed was located at the C terminus.

Amino Acid Sequence↗
PubMed2001

[Pilot study on mutations of p53 gene in laryngeal carcinoma].

OBJECTIVE: To determine the characteristic and frequency of the point mutation of p53 gene. METHODS: 22 cases of laryngeal squamous cell carcinoma (LSCC) with positive expression of mutant p53 protein and 2 cases of normal laryngeal epithelium as control were examined by means of polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP), single strand conformation polymorphism (SSCP) and DNA sequencing analyses. RESULTS: 3 cases of LSCC had the point mutation on codons 248, 250 and 254 of exon 7 in p53 gene. None of the cases had the point mutation on codon 249. CONCLUSION: These findings suggest that the point mutation on codon 249 of exon 7 in p53 gene may be uncommon in LSCC. SSCP and DNA sequencing analyses are sensitive and rapid methods for detecting p53 gene mutation.

Adult↗
PubMed2001

[Analysis on the sex ratios at birth for deliveries in hospitals in China from 1987 to 1992].

OBJECTIVE: To estimate the sex ratios at birth (SRB) for livebirths in hospitals in China. METHODS: Data were collected by the birth defects monitoring network. The livebirths with gestation of 28 weeks or over delivered in hospitals of 30 provinces, municipalities and autonomous regions all over the country from 1987 to 1992 were analyzed and used for calculating the SRB. RESULTS: The high male bias in SRB was observed in the data from most areas, and there was an upward trend of SRB, especially in rural areas. The SRB for livebirths in the hospitals of urban areas was normal from 1987 to 1989, and rose to 108.9 in 1992. The SRB for rural areas was high and was 109.9 in 1987, and rose to 111.8 in 1992. The SRB for livebirths given by the mothers under 20 years of age and coming from lower educational background was higher than that for others. The SRB for higher parities was even higher. CONCLUSION: The SRB in China is high; this is possibly related to sex-preference. Under-reporting of female neonates and "missing females" are not the main causes of the rising SRB.

China↗
PubMed2001

[A multi-centered clinical study an domestic intravenous Turbutalin sulfate in the treatment of asthma and chronic asthmatic bronchitis].

OBJECTIVE: This multi-centered clinical trial was designed to assess the efficacy and safety of domestic intravenous Turbutalin Sulfate in the treatment of asthma and chronic asthmatic bronchitis. METHODS: Bricanyl was used as control. A total of 120 patients were included in this randomized controlled study. The two medications, both at a dose of 0.25 mg intravenous drip, were given three times a day for 3-5 days. RESULTS: The two drugs' clinical excellent rates were 66.7% and 73.3%; overall efficacy rates were 98.3% and 100.0%, respectively. Their pulmonary functional excellent rates were 78.4% and 76.6%; overall effect rates were 88.3% and 90.0%, respectively. Composite curative evaluation showed that the two drug's composite excellent rates were 61.6% both; their overall efficacy rates were 88.3% and 90.0%, respectively. All of these showed no significant difference (P > 0.05). The incidence rates of adverse side effects of the two groups were 13.5% and 15.0%, respectively; most of them were mild and tolerable. CONCLUSION: Domestic intravenous Terbutalin Sulfate is effective and safe in treating asthma and chronic asthmatic bronchitis.

Adolescent↗
PubMed2001

[Study on the photoluminescence spectrum of nickel passivation treatment of porous silicon].

A new method for electrolysis passivation treatment of porous silicom (PS) in NiCl2 is reported in this paper. The photoluminescence (PL) spectra of PS treated in different time is observed, the spectra show that peak intensity is 2.5 times stronger than that without treatment, peak wavelength is 33 nm blue shift when PS is treated properly. The phenomenon caused is that the results of the SiHx change into SiNix when replaced H by Ni on surface of PS.

Chemical Phenomena↗